Search: keyword:perfect
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BP321 |
| Small round object unreachable from the border of the box vs. small round object reachable from the border of the box. |
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COMMENTS
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Equivalently, "small round object enclosed by white loop vs. not so." |
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CROSSREFS
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Adjacent-numbered pages:
BP316 BP317 BP318 BP319 BP320  *  BP322 BP323 BP324 BP325 BP326
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KEYWORD
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nice, precise, allsorted, boundingbox, perfect, pixelperfect, traditional, bordercontent
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CONCEPT
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bounding_box (info | search), path (info | search), reachable (info | search)
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AUTHOR
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Aaron David Fairbanks
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BP324 |
| Left shapes can be placed on top of each other to make right shape vs. not so. |
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BP325 |
| Left shapes can combine by symmetric difference (XOR logical operator) to make right shape vs. left shapes can combine by intersection (AND logical operator) to make right shape. |
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BP335 |
| Tessellates the plane vs. does not tessellate the plane. |
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COMMENTS
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EX7152 is an example of a shape than can be stretched in such a way that it no longer tessellates the plane. This is a property that is only exhibited by shapes that tessellate with rotated copies of themselves. - Leo Crabbe, Mar 05 2021 |
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CROSSREFS
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Adjacent-numbered pages:
BP330 BP331 BP332 BP333 BP334  *  BP336 BP337 BP338 BP339 BP340
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KEYWORD
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nice, stretch, unstable, math, hardsort, creativeexamples, proofsrequired, perfect, pixelperfect, traditional
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CONCEPT
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infinite_plane (info | search), tessellation (info | search), tiling (info | search)
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WORLD
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shape [smaller | same | bigger] zoom in left (fill_shape)
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AUTHOR
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Aaron David Fairbanks
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BP341 |
| Strictly increasing or strictly decreasing border line vs. both increasing and decreasing border line. |
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BP344 |
| Shape can tile itself vs. shape cannot tile itself. |
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COMMENTS
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Left examples are sometimes called "rep-tiles."
The tiles all must be the same size. More specifically, all left examples can tile themselves only using scaled down and rotated versions of themselves with all tiles the same size. Right examples cannot tile themselves using scaled down rotated versions of themselves or even reflected versions of themselves with all tiles the same size.
Without the puzzle piece-like shape EX4120 on the right side the current examples also allow the solution "shape can tile with itself so as to create a parallelogram vs. shape cannot tile with itself so as to create a parallelogram." |
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CROSSREFS
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See BP532 for a version with fractals.
Adjacent-numbered pages:
BP339 BP340 BP341 BP342 BP343  *  BP345 BP346 BP347 BP348 BP349
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EXAMPLE
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Go to https://oebp.org/files/yet.png for an illustration of how some left-sorted shapes tile themselves. |
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KEYWORD
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hard, precise, notso, unstable, math, hardsort, creativeexamples, proofsrequired, perfect, traditional
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CONCEPT
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recursion (info | search), self-reference (info | search), tiling (info | search), imagined_shape (info | search), imagined_entity (info | search)
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WORLD
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shape [smaller | same | bigger]
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AUTHOR
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Aaron David Fairbanks
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BP348 |
| Shape on the right is the convex hull of shape on the left vs. not so. |
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BP367 |
| Center of mass within the black area of the shape vs. center of mass out of the black area of the shape. |
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BP368 |
| There is a point that can see (in straight lines) all points vs. there is no point that can see (in straight lines) all points. |
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BP386 |
| Lower shape can be used as a tile to build the upper one vs. not so. |
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CROSSREFS
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Adjacent-numbered pages:
BP381 BP382 BP383 BP384 BP385  *  BP387 BP388 BP389 BP390 BP391
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KEYWORD
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nice, precise, allsorted, left-narrow, perfect, pixelperfect, orderedpair, traditional, preciseworld, left-listable, right-listable
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CONCEPT
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tiling (info | search)
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AUTHOR
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Jago Collins
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